<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>

        div {
            width: 300px;
            height: 300px;
            border: 1px solid #000;
            margin: 10px auto;
        }

        /* 径向(圆形)渐变色 */
        div:nth-child(1) {
            background: radial-gradient(at left top, yellow, blue);  /* [辐射半径]圆心位置,起始颜色,终止颜色 */
        }

        div:nth-child(2) {
            background: radial-gradient(100px at left top, yellow, blue);   /* 辐射半径 圆心位置 */
        }

        div:nth-child(3) {
            background: radial-gradient(at 100px 100px, yellow, blue);   /* 圆心位置可以是像素值 */
        }

        div:nth-child(4) {
            background: radial-gradient(at center, yellow 0%, blue 30%, red 70%, purple 100%);  /* 多种颜色,百分比表示渐变半径上的位置 */
        }

    </style>
</head>
<body>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
<div class="box"></div>
</body>
</html>
